1. Field of the Invention
The invention relates to a method and a device for the production of a printing block. The printing block may, for example, be a flexible printing block or an inflexible printing block, which can act as a relief printing or gravure printing block.
2. Description of the Relevant Art
To produce a flexographic printing block with the aid of a conventional CO2 laser it is already generally well known for material to be burned out directly from a printing plate, which may be a polymer plate for instance, in order in this manner to produce a relief in the printing plate. In this process, however, the COZ laser is permanently power-modulated so that the process is relatively slow.
Furthermore, for the production of a flexographic printing block PCT/EP96/05277 already discloses the use of two laser beam sources in order with the first laser beam source to obtain fine structures in a desired profile, while by means of the second laser beam source low-level regions in the profile are produced.
Fine and simultaneously low-level regions cannot be produced in this way at relatively high operating speed by the two methods mentioned above without further measures. Power modulation on its own is too sluggish for this purpose, while if an acousto-optical modulator is used the laser power must be limited to relatively low levels in order not to destroy the modulator.